First total eclipse of the moon in 3 years tonight

LONDON -- The moon will turn shades of amber and crimson Saturday night as it passes behind the Earth's shadow in the first total lunar eclipse in three years.

The eclipse will be at least partly visible from Asia to the Americas, although those in Europe, Africa and the Middle East will have the best view.

Lunar eclipses occur when Earth passes between the sun and the moon, blocking the sun's light. The event is rare because the moon spends most of its time either above or below the plane of Earth's orbit.

Although it will pass completely under Earth's shadow, light from the sun will still reach the moon after being refracted through Earth's atmosphere, giving the moon an eerie dark reddish tinge.

"It's not an event that has any scientific value, but it's something everybody can enjoy," said Robert Massey of the Royal Astronomical Society.

Earth's shadow will begin moving across the moon at 2:18 p.m. CST today, with the total eclipse occurring at 4:44 p.m. and lasting more than an hour.

Observers in eastern North America and South America will find the moon already partially or totally eclipsed by the time it rises over the horizon this evening.

Alaska, eastern Australia and New Zealand will miss the show altogether.

The next total lunar eclipse will occur Aug. 28.